iodoquinol

Action and Spectrum

Contraindications/caution: 

Contraindications: 

• iodoquinol is contraindicated in patients with known hypersensitivity or allergy to the medication or its components. It should not be used in patients with a history of optic neuropathy, including optic neuritis or atrophy, or with pre-existing visual disturbances 
• iodoquinol is also contraindicated in patients with severe liver disease or renal impairment. It should be used cautiously in patients with hepatic or renal impairment, as the drug is metabolized in the liver and excreted in the urine. In these patients, the dose of iodoquinol may need to be adjusted to prevent drug accumulation, and toxicity 
• iodoquinol should not be used in pregnant women unless the potential benefits outweigh the risks. It is not known whether iodoquinol can pass into breast milk, so breastfeeding women should also use caution and consult with their healthcare provider before taking this medication 

Caution: 

Several cautions should be taken into consideration when using iodoquinol: 

• Neurotoxicity: iodoquinol can cause neurotoxicity, mainly when used at high doses or for prolonged periods. Symptoms of neurotoxicity may include headache, dizziness, confusion, and visual disturbances. Patients should be monitored for these symptoms, and the drug should be discontinued if they occur 
• Gastrointestinal disturbances: iodoquinol may cause gastrointestinal disturbances, such as nausea, vomiting, and diarrhea. These symptoms are usually mild and resolve spontaneously, but patients should be monitored, and the drug should be discontinued if severe symptoms occur 
• Hypersensitivity reactions: iodoquinol can cause hypersensitivity reactions, such as rash, itching, and swelling. In severe cases, anaphylaxis may occur. Patients should be monitored for these reactions, and the drug should be discontinued if they occur 
• Interactions with other medications: iodoquinol may interact with other medications, including anticoagulants and antiarrhythmic drugs. Patients taking these medications should be monitored closely while taking iodoquinol 
• Use in paediatric patients: The safety and efficacy of iodoquinol have not been established, so caution should be used when prescribing this drug to children 
• Use in elderly patients: Elderly patients may be more susceptible to the neurotoxic effects of iodoquinol, so caution should be used when prescribing this drug to older adults 

Drug Interaction

Adverse Reaction

Frequency not defined 

Atrophy 

Abdominal amnesia 

Nausea 

Vomiting 

Peripheral rectal impairment 

Optic of neuritis 

Stomach Headache 

Chills 

Agitation 

Diarrhea 

Rash 

Fever 

Urticaria 

Pruritus 

Thyroid cramps 

Itching gland neuropathy 

Optic area pain 

Weakness 

Visual enlargement 

Retrograde 

Black Box Warning

Contraindication / Caution

Actions and spectrum: 

iodoquinol is an antiprotozoal medication that works by interfering with the metabolism and reproduction of protozoa. It is believed to exert its action by binding to DNA and interfering with the energy metabolism of the protozoa. This leads to the inhibition of protein synthesis and, ultimately, the parasite’s death 

iodoquinol has activity against several protozoa, including: 

• Entamoeba histolytica: iodoquinol is effective against Entamoeba histolytica, a protozoan parasite that can cause amebic dysentery, liver abscesses, and other serious infections 
• Giardia lamblia: iodoquinol is effective against Giardia lamblia, a parasitic infection that causes diarrhea, abdominal cramps, and bloating 
• Cryptosporidium parvum: iodoquinol has been used to treat Cryptosporidium parvum, a parasite that can cause severe diarrhea in immunocompromised individuals 
• Dientamoeba fragilis: iodoquinol has been used to treat Dientamoeba fragilis, a protozoan parasite that can cause diarrhea, abdominal pain, and other gastrointestinal symptoms 
• Blastocystis hominis: iodoquinol has been used to treat Blastocystis hominis, a parasite that can cause gastrointestinal symptoms such as diarrhea, abdominal pain, and bloating. 

Overall, iodoquinol has a broad spectrum of activity against several protozoa, particularly those causing intestinal infections 

Pregnancy / Lactation

Pregnancy consideration: C 

Lactation: Excretion of the drug in human breast milk is unknown 

Pregnancy category: 

Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester.   

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.    

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: There is no data available for the drug under this category 

Pharmacology

Pharmacology: 

iodoquinol is an antiprotozoal drug primarily used to treat intestinal protozoal infections such as amebiasis and giardiasis. The drug works by inhibiting the growth and replication of the protozoal cells, leading to their eventual death 

iodoquinol is believed to work by interfering with protozoal DNA synthesis, inhibiting nucleic acid synthesis. The drug has also been shown to inhibit the enzyme pyruvate-ferredoxin oxidoreductase, which is involved in the energy metabolism of protozoal cells 

Pharmacodynamics: 

Specifically, iodoquinol inhibits the electron transport chain in the mitochondria of the parasites, which interferes with their ability to generate ATP and other essential metabolic processes. This leads to the parasites’ death and the infection’s resolution 

Pharmacokinetics: 

Absorption 

iodoquinol is administered orally, and it is rapidly and almost completely absorbed from the gastrointestinal tract. It is recommended to be taken with food, which enhances absorption 

Distribution 

iodoquinol is distributed throughout the body but has a relatively low volume of distribution. It is highly protein-bound, primarily to albumin 

Metabolism 

iodoquinol undergoes extensive metabolism in the liver. It is metabolized by cytochrome P450 enzymes, primarily CYP3A4, to several metabolites, including diiodoquinol, the major metabolite. These metabolites are then excreted in the urine and feces 

Elimination and Excretion 

iodoquinol and its metabolites are primarily eliminated by the kidneys, with approximately 60% excreted unchanged in the urine. The remaining amount is excreted in the feces

Adminstartion

Administration: 

Dosage: 

The dosage of iodoquinol depends on the type and severity of the infection being treated and the patient’s age and weight. It is typically taken three times a day for 20 days.  

Oral Administration:  

iodoquinol is available in tablet form and is taken orally. It is recommended to be taken with food to enhance its absorption 

Patient Information Leaflet

Patient information leaflet 

Generic Name: iodoquinol 

Why do we use iodoquinol? 

iodoquinol is an antiprotozoal medication that is primarily used for the treatment of intestinal infections caused by protozoan parasites, including: 

• Entamoeba histolytica: It is effective against this parasite’s active and cyst forms, which can cause amoebic dysentery and liver abscesses 

• Giardia lamblia: It is effective against this parasite’s trophozoite and cyst forms, which can cause giardiasis, a diarrheal illness 
• Cryptosporidium parvum: It has some effectiveness against this parasite, which can cause diarrhea, especially in immunocompromised individuals 

In addition to its antiprotozoal properties, iodoquinol has been studied for its potential use in the treatment of other conditions, including: 

• Cervical dysplasia: It has been investigated as a topical treatment for cervical dysplasia, a pre-cancerous cervix condition 
• Cutaneous leishmaniasis: It has been studied as a potential treatment for cutaneous leishmaniasis, a parasitic infection that can cause skin lesions